The Mariners are expected to have Austin Jackson and Chris Denorfia in the lineup Friday night when they open a three-game set with the Orioles, who will have Andrew Miller in the bullpen.Seattle (56-52) got a two-run homer from Mike Zunino in the eighth inning Thursday to win 6-5 at Cleveland, remaining three games behind Toronto for the AL's second wild-card spot.The Mariners feel they improved their odds at closing that gap, acquiring Jackson and Denorfia in separate deals before Thursday's non-waiver trade deadline."We were looking for right-handed bats," general manager Jack Zduriencik told MLB's official website. "Now we've got a leadoff pure center fielder (in Jackson) and that's going to help a lot, and Denorfia has really good numbers against left-handed pitching."He's a tough kid that's been through the playoffs and knows it. Same thing with Austin Jackson, he's been there, done that. So bringing the veteran experience to the ballclub at this time of the year was a really important factor."Jackson was hitting .388 with eight doubles and 15 runs over his last 19 games with Detroit, and manager Lloyd McClendon is well aware of his capabilities after spending eight years as the Tigers' hitting coach."He's good on top of the order, he steals bases, and he's a veteran hitter," McClendon said.Denorfia was batting .242 for San Diego this year, but he's a career .301 hitter versus lefties.Seattle is hoping that pays immediate dividends, as southpaw Wei-Yin Chen (11-3, 3.92 ERA) gets the ball for Baltimore (60-47).He's facing the Mariners for the second straight start, and his last one was among the best of his three-year career. He didn't allow a runner to reach second base after the first inning and left after the eighth of a 4-0 win at Seattle on July 24."Probably the best I've seen (Chen) in a really long time," catcher Caleb Joseph told MLB's official website.After seeing Chen throw a season-high 109 pitches, though, manager Buck Showalter opted to give him a few extra days between starts."Wei-Yin had his top pitch count of the year and I want to keep guys on turn," Showalter said.Chen has won a personal-best four starts in a row behind a 2.92 ERA.Miller will be available to relieve him after being acquired from Boston for pitching prospect Eduardo Rodriguez on Thursday. The left-hander has a 2.34 ERA on the season and joins a bullpen that's allowed three runs in 26 1/3 innings during a 5-2 stretch."He gives us more depth down there, keep passing the load around," Showalter said. "I think he's a little more than just a left-handed arm. You look at left-handed relievers, the ideal ones are the guys that you've got left-right-left and you can leave them in there for the right."Baltimore, which won three of four in Seattle last week, is atop the East by 1 1/2 games on the second-place Blue Jays.Each of the Orioles' last six games have been decided by one run, including Thursday's 1-0, 13-inning defeat to the Los Angeles Angels.They'll try to get their offense back on track against Roenis Elias (8-8, 4.31), who allowed one run with six strikeouts in five innings of a 3-2 win in 10 over Baltimore on Sunday.The left-hander was limited to 85 pitches, however, after cramping in his forearm forced him to exit a 5-2 win over the New York Mets six days earlier. He yielded one run with eight strikeouts in 5 1/3 innings that day, ending a personal three-game losing streak that included a 10.05 ERA.